drm/xe: Fix whitespace in register definitions

Our register headers use tabs to align the definition values.  Convert a
few definitions that were using spaces instead.

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20231214184659.2249559-13-matthew.d.roper@intel.com


Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>